Issue Type Mapping - Requirement type missing

Hello,

I installed Xray with Jira (server configuration).
As an administrator, I display the "Issue Type Mapping" screen.
(http://confluence.xpand-it.com/display/XRAY/Issue+Type+Mapping)
But the Requirement type is missing on my screen (refer to the print screen joined).

I created tests, test sets, ... But, I can't create requirements.

Could you solve my problem ?

Regards,

Didier